Does anyone know what coats the engine block? My engine block's surface is chipped underneath the front end. It is a little tough to see from the below picture but the coating is definitely chipped to the base material.
Will the block begin to rust and is there something I can apply to protect it?
(https://farm5.static.flickr.com/4024/4654212876_13d1b1a150.jpg)
I believe that it is just paint, and I also believe that the block is aluminum, so it wont "rust". It may however start to oxidize.
the paint on my engine is peeling off the same way, but in more than 1 spot. im planning on stripping it and repainting it with something more durable.
it wont rust like iron does, but it still "rust" or rather it oxidies into this hazy white finish that is dry to the touch. wont harm the aluminum.
Quote from: He Man on May 30, 2010, 02:19:56 PM
the paint on my engine is peeling off the same way, but in more than 1 spot. im planning on stripping it and repainting it with something more durable.
it wont rust like iron does, but it still "rust" or rather it oxidies into this hazy white finish that is dry to the touch. wont harm the aluminum.
Until it's all gone.
The white powder is aluminum oxide.
Rust is iron oxide.
After time they both 'rot' away.
Quote from: ducpainter on May 30, 2010, 02:35:24 PM
Until it's all gone.
The white powder is aluminum oxide.
Rust is iron oxide.
After time they both 'rot' away.
it'll be a long time before the aluminum rots away unless you spend every waking second rubbing the aluminum oxide away.
Quote from: He Man on May 30, 2010, 03:35:36 PM
it'll be a long time before the aluminum rots away unless you spend every waking second rubbing the aluminum oxide away.
True...
but your statement of...
Quote from: He Man on May 30, 2010, 02:19:56 PM
<snip>or rather it oxidies into this hazy white finish that is dry to the touch. wont harm the aluminum.
is pretty inaccurate.
Quote from: ducpainter on May 30, 2010, 03:49:15 PM
True...
but your statement of...
is pretty inaccurate.
Can you clarify? the oxidation layer should protect the raw aluminum underneath.
I have a 1964 250 single that was sandblasted in 1967 that except for the oxidation looking bad is still sound. it'll last longer than you will.
Quote from: He Man on May 30, 2010, 08:27:38 PM
Can you clarify? the oxidation layer should protect the raw aluminum underneath.
If that were the case wouldn't rust protect the metal underneath?
That would mean cars would never perforate from rust which obviously doesn't happen.
I realize that the casting that makes up our crankcases is thick enough to out last us.
My only point is bare aluminum does get harmed from oxidation.
Quote from: ducpainter on May 31, 2010, 01:39:48 AM
If that were the case wouldn't rust protect the metal underneath?
Rust is the term for Iron oxide or any iron based metal that oxidizes.
Aluminum oxide is not called rust
and if iron rusted teh same way aluminum did, it would protect the base metal. It just so happens it doesnt. Iron rust in huge chunks and gets flakey, and when it lifts it exposes new iron and the process continues till it eats it away.
Quote from: He Man on May 31, 2010, 07:13:21 AM
Rust is the term for Iron oxide or any iron based metal that oxidizes.
Aluminum oxide is not called rust
and if iron rusted teh same way aluminum did, it would protect the base metal. It just so happens it doesnt. Iron rust in huge chunks and gets flakey, and when it lifts it exposes new iron and the process continues till it eats it away.
I understand the difference. I can read.
I've been working with metal longer than you've been alive. Maybe longer than your father has been alive.
Just because it isn't called rust doesn't make it good.
Oxidation is bad for all metals.
All oxidation harms metal.
If that wasn't the case the aerospace industry wouldn't have such strict anti-corrosion processes to control corrosion.
How many planes have to crash from corroded aluminum parts before you believe it's an issue? [roll]
I'm not sure that the oxidation of Aluminum has the same repercussions (short term) as that of carbon based steel. It does however break down the chemical makeup. Therefore it will affect the long term stability of the alloy. Steel will be affected by the process much sooner than aluminum so in a way you are both correct. I think that by the time that the oxidation's affect the aluminum to the point of failure, the bike will have many other issues. So to say that it's not going to hurt it any, well not in the bikes life time. Than again, if he is still riding it in 40 years, yeah it will be a concern.
Saw this discussion, thought I'd throw in a couple pennies...
I suppose this point has already been made but rust is oxidation. It is oxidation of iron and other ferrous alloys. Lots of metals oxidize in different ways based on their chemical properties and the substances they react with.
This also makes it true that the oxidizing rate of cast aluminum is slower than that of say, mild steel, given the same environmental conditions. The structures created by the formation of aluminum oxide typically do form a dense and nonreactive layer above the aluminum object. But it is still penetrable by most liquids and gases, and the aluminum object will continue to corrode so long as it is exposed to the environment which initiated the corrosion. This is typical of the oxidation of most metals, BUT, there is at least 1 exception I can think of right off hand.
And while its not really relevant to monsters, or motorcycles (save for some crush washers and other odd bits), copper is one such metal which is not ultimately destroyed from water oxidation. This is one reason why it is used in your house's plumbing (in addition to being naturally antimicrobial). The oxidation layer that forms on the inside of the copper pipes forms quickly, but remains thin because the layer is so dense, it blocks the water from contacting and reacting with the pure copper.
Of course none of this is likely new information for most yous guys, but since when are a couple pennies something new to somebody anyways?
Quote from: ducpainter on May 31, 2010, 11:26:30 AM
All oxidation harms metal.
If that wasn't the case the aerospace industry wouldn't have such strict anti-corrosion processes to control corrosion.
How many planes have to crash from corroded aluminum parts before you believe it's an issue? [roll]
Planes go through extreme temp differences, pressure differences, and any corrosion gets blasted off, exposing new metal until it gets painted. Though true, It has no valid point in my argument which is, If you leave the oxidation layer alone in the case of Aluminum, it will not continue to eat through.
Start washing the layer off every day and neglecting it on something that keeps weight to a minimum and has huge forces applied to it and you almost have to be the worst gambler in the world to say it wont eventually fall out of the sky.
Quote from: He Man on May 31, 2010, 09:05:25 PM
Planes go through extreme temp differences, pressure differences, and any corrosion gets blasted off, exposing new metal until it gets painted. Though true, It has no valid point in my argument which is, If you leave the oxidation layer alone in the case of Aluminum, it will not continue to eat through.
Start washing the layer off every day and neglecting it on something that keeps weight to a minimum and has huge forces applied to it and you almost have to be the worst gambler in the world to say it wont eventually fall out of the sky.
Are you going to be an ME?
I guess corrosion inside a wing structure gets blasted off all the time. ???
You totally miss the point, and I'm bored with trying to convince you that oxidation of aluminum is harmful.
Why are you painting
your engine?
http://corrosion-doctors.org/Aircraft/Aloha.htm (http://corrosion-doctors.org/Aircraft/Aloha.htm)
Grew up in the tropics. Hatred for corrosion is encoded in my genes. Protect all metals, all the time. Rust never sleeps.
If you like aluminum, you treat it with a weak phosphoric acid solution and then chromic acid. No need to tank it, you can just brush it on. Use scotchbrite to clean the white oxide before the phosphoric acid. After that you can prime and paint if you want.
Iron rust molecules are physically larger than non corroded molecules, that is why iron and steel flake off so dramatically. Aluminum oxide doesn't have as big a dimensional problem, but it weakens the structure and flakes off too. The initial layer of corrosion in aluminum does form a coating that slows down the oxidation to some extent, but it does not stop, and it becomes really bad when exposed to road salts or stressed. You end up getting pinholes and stress cracks. The structural alloys in our parts, whatever they are, are more corrosion prone that pure aluminum.
If you are studying engineering, think of everything wanting to go to the lowest energy and highest disorder state. The lowest energy state of metals is a pile of rust. It takes energy to convert and maintain that pile of rust into the ordered shape of the engine cases. You must spend energy to prevent corrosion from raising the entropy of the cases until they become a pile of stable dust. (sorry for the trip down memory lane)
Im not going to keep going with this. I agree with both of you guys. It just seems like we are talking about 2 different things here.
Aluminum Oxide, formed by O2 exposure. Will make the protective coating and it will not continue to rust. If you start talking about other oxidation states fromed by other elements, some of them will penetrate teh oxidation layer and continue. But O2 wont. Thats my point. But in practice. It depends on where you live that will determine the ultimate outcome Northeast, rust belt, sun belt. etc.
And to ducpainter, no im not an ME and plane wings stretch, bend, expand, compress, all that stuff will knock off the oxidation layers + moisture inside the wing from humidity and temp differences.
And im painting my engine cause of the conditions i ride in. The Aluminum on my engine block will oxidize, then itll get blown off by a rock, salt water spray, make the beast with two backsing acid rain, tar, random chemicals that factories throw into the streets.
and most importantly, itll get on my white shirt cause im a squid in the summer. ;D
btw: your all right anyway. Practice over concept. Oxidation is bad and should be avoided at all cost unless your looking to harvest the oxdation.
This conversation hurts me so.
Just paint the dang thing.
Quote from: garp2112 on May 30, 2010, 01:48:03 PM
Does anyone know what coats the engine block? My engine block's surface is chipped underneath the front end. It is a little tough to see from the below picture but the coating is definitely chipped to the base material.
Will the block begin to rust and is there something I can apply to protect it?
(https://farm5.static.flickr.com/4024/4654212876_13d1b1a150.jpg)
so, to the op's question...is there something he can apply, besides actually going through the process of engine removal and total repainting of the block? mine is doing the same thing on the alternator cover side...towards the front. everywhere else it's fine, though...so this isn't something i want to have to remove the cover for (for the time being at least... and definitely not during riding season). is there something you can apply in the interim until you get to the colder months, that doesn't look completely ghetto? maybe it's just not even that big of a deal to worry about...but i just hate seeing it flaking like that. i have this urge to pick of the flaking bits or sand it down and coat it with something protective, for now at least.
Quote from: ♣ McKraut ♣ on June 01, 2010, 09:44:50 AM
so, to the op's question...is there something he can apply, besides actually going through the process of engine removal and total repainting of the block? mine is doing the same thing on the alternator cover side...towards the front. everywhere else it's fine, though...so this isn't something i want to have to remove the cover for (for the time being at least... and definitely not during riding season). is there something you can apply in the interim until you get to the colder months, that doesn't look completely ghetto? maybe it's just not even that big of a deal to worry about...but i just hate seeing it flaking like that. i have this urge to pick of the flaking bits or sand it down and coat it with something protective, for now at least.
It can be treated with Alodine, but the location of the damage will require a durable coating, paint, to make it last.